You've probably never seen Liz. That was the American title for the erotic Swedish film I lust och nöd, released heavily edited in the UK as Private Pleasures. And if you watch this trailer you still won't have seen any of Liz. This amazing trailer uses absolutely no footage from the film to sell the movie. The conceit is that the film - falsely claimed to have been banned in 30 countries - is too shocking to show in the trailer, so they trot out a bunch of people to talk about their experience watching the movie. Some of them are old ladies. And then the 'producer' shows up to explain how Liz isn't smut but rather a serious examination of a young woman driven mad by her own lust.
It's great! I don't know how successful this approach ended up being, but I know that it makes for a delightful trailer to watch now, in retrospect.